Apparatus for supplying oxygen to combustion chambers



y 1929- A. o. HIGINBOTHAM 1,711,944

APPARATUS FOR SUPPLYING OXYGEN TO COMBUSTION CHAMBERS Original Filed Aug 15, 1924 2 Sheets-Sheet l INVENTOR.

lv l. May 7, 1929. I A. o. HIGINBOTHAM 1,711,944

APPARATUS FOR SUPPLYING OXYGEN 'JI'O COMBUSTION CHAMBERS 7 Original Filed Au 15, 1924 2 Sheets-Sheet 2 INVENTOR.

. d. afl yuzaihwc Patented May 7, 1929.

NlE STA'l'S PATENT oFFicE.

ARTHUR O. HIGINBOTHAM, E DENVER, COLORADO, ASSIGNOR OF ONE-HALF TO WIL- LIAM A. WEIGELE, 0F DENVER, COLORADO.

APPARATUS FUR SUPPLYING OXYGEN TO COMBUSTION CHAMBERS.

Original application filed August 15, 1924-, Serial No. 732,323.

This invention. relates to an improved mechanism for the controlled supply of oxy gen to the fire bed of a boiler or other furnace, after its replenishment with fres-ih fuel,

to effect a substantially complete combustion of the gases emanated from the burning fuel and thereby prevent the formation of smoke and escape of partially oxidized and unoxidized combustible gases and the conse quent waste of heat units.

It is an object of the invention. to provide a simple, practical and ei'licient mechanism which is automatically actuated after the furnace is supplied with fuel, to admit oxygen to the fire at a predetermined rate and during a predetermined space of time.

A further object of the invention is to inelude in the above stated mechanism, readily efi'ected adjustments whereby the oxygen supply may be varied in accordance with different requirements and another aim of the invention resides in carrying the above objects into efiect by means of a cam-operated damper, and a time mechanism for the operation of the damper.

In the accompanying drawings, the invention has been illustrated in operative relation to the hinged fire-door of a furnace but it is to be understood that a diil erent moving part of a furnace, as, for example, the reciprocating piston ram of a mechanical pushstoker, may be employed for the same purpose without material changes in the construction or arrangement of the elements of the invention,

In the accompanying drawings in which similar characters of reference designate corresponding parts'throughout the several views.

Figure 1. represents a front view. ofa portion of a furnace wall and a door closing the fireopening thereof, with the elements and parts comprised in the present invention in operative relation thereto, the casing en closing the timeelement of the mechanism having been shown in vertical section;

Figure 2, an enlarged vertical section along the line 2--2, Figure'l;

Figure 3, a similar section taken along the line 3 3, l igure 1;

Figure 4, an enlarged section in the plane indicated by the line e in Figure 1;

Figure 5, section similar to that ofl igare showing the members of the cam- Divided and this application filed July Serial No. 43,644.

movement in the position they occupy when the dampers of the furnace have been opened to the full extent of their predetermined movement ure 6, a fragmentary enlarged section along the line 6-6, Figure 1;

.ifiigure 7, a sectional detail of the adustable anti-friction wheel which transmits the movement of the cam-element of the invention to the dampers which control the admission of oxygen to the fire boX of the furnace; and

l igure 8, anenlarged face-view of the cam-element of the invention.

The present application is divisional of my application for Patent No. 732,323, filed on the th day of August-1924.

Referring to the drawings, 5 designates the wall of a boiler or furnace, having a fireopening and a door 7 hinged at'8, which normally closes the same.

The door has an opening defined by a forwardly projecting rectangular flange 9, through which, in practice, air is admitted to the combustion chamber of the furnace, and the air-opening is normally closed by two lapping dampers 1O hung for pivotal movement about'horizontal axes, by means of shafts 12 supported in openings of the flange.

The door has the'usual handle 13 by which it is opened and closed.

The dampers are automatically opened and closed when the door has been opened for replenishment of the fuel, by a time mechanism of the, escapement type indicated in its enti 'ety by the reference character 14.

The time movement includes a gear-train l5 and an'escapement in which two opposed weights l6v mounted for simultaneous ad justment at the upper end of a vertical shaft 17 to regulate the operation of the mechanism bv their distance from the axis of oscillation of the shaft. 1

The time mechanism is enclosed in a dustproof casing 18 which is fastened upon the door of the furnace at a side of the rec tangular flange which defines the air-opening controlled by the dampers. 7

An oscillating lever 19 loosely supported on the spindle 20 of the driving Wheel 21 of the time movement, exteriorly of thecasmay carries a pivoted pawl 22 which nory engages with a notched wheel 23fixed at the end of the spindle, to impart a rotary movement thereto, the arcuate movement oi. the lever being limited by two stops 2-l and 25.

The time mechanism is operated by a coiled spring 26 disposed between a shoulder 2? on the lever and a thereto opposed shoulder 28 of a bell crank 29 mounted in bearings 30 on the door below the flange, and a rod 81 fastened to the lever and moving freely through an opening in the shoulder of the bell. crank, extends through the spring to prevent its lateral deflection.

A pin 32 on the arm of the bell crank opposite that engaged by the spring, passes freely through an opening of the door to engage the frame of the boiler around the fire opening when the door is in the closed position.

When the fire door of the furnace is opened for the purpose of supplying the fire in the combustion chamber or the same, with fresh fuel, the pin on the bell crank is projected through the opening of the door by gravity of the parts with which it is associated and the lever 19 is by the same influence moved to the position shown in Figure 2, it being understood that the opening in the door is sufficiently wide to permit oi the slight lateral displacement of the pin caused by the arcuate movement of the end of the bell crank arm with which it is connected.

hen after the fire has been coa-led, the pin by contact with the furnace wall, compels the bell crank to move about its axis, the spring is compressed against the shoulder of the lever 19 held through the medium of the pawl 22 by the frictional resistance of the time-mechanism of which it is a part.

The subsequent expansive movementof the spring operates the time mechanism at a rate regulated by the escapement, until the lever engages the stop 25 when the operation is automatically discontinued.

\Vhen the spring is compressed as stated hereinabove, the bell crank occupies a position in which its upper arm extends at so small an angle to a iierpendicular passing through the axis of its shaft, that the force resulting from the expansion of the spring will be mostly exerted upon the lever 19 of the time mechanism, while its tendency to open the fire door by downward movement of the bell crank is negligible.

The time mechanism, thus actuated by the spring, effects the movement of a shaft 33 wh ch is mounted to rotate in openings of the upright portions of the door-flange and which at the side of the flange opposite to the time-mechanism, carries a cam-element 34 by which the. dampers ot the door are opened and closed.

The cam-element in its simplest form consists of a disk having a peripheral, preferably grooved, edge of irregular form.

The edge of the cam is engaged by an anti-triction wheel 35 on the elongated wrist rod 36 of a crank 37 at the adjacent end of the shaft of the upper damper, and a bar 38 connecting said rod with the wrist of a corr pondingly positioned crank 39 on the sh: .t of the lower damper provides for the conjoint movement of the dampers.

It is preferred to compose the cam element of a number of steps oi? corresponding outlines but progressively decreasing diameters best shown in Figure 8, to permit of varying the extent to which the dampers are opened in the operation of the time-mechanism, and the wheel is slidable on the wrist rod 36 for its adjustment from one step of the cam-element to another across the entire width thereof.

When the tire door is closed, the time mechanism is in a condition of inactivity, and. the dampers close the opening defined by the flange oi the door as shown in Figures 1 and 8. The wheel on the crank of the upper damper engages at the periphery of the step of the cam element corresponding with the extent to which the dampers are to be opened and the pawl 22 on the lever 15) is in engagement with the notched wheel 2' on the shalt ot' the driving Wheel of the time-mechanism.

lVhen in replenishing the fire in the fur nace, the fire door is opened and closed, the consequent actuation of the time mechanism as hereinbefore described, causes the shaft to rotate with the result that through the medium of the cam element the dampers of the door are gradually opened at a rate determined by the peripheral shape of the cam with which the wheel of the crank movement is in contact.

Thus, when the cam rotates in the direction of the arrow, the dampers are opened by upward movement of the wheel 35 until the latter has reached the highest point of its movement by engagement with the cam at its point of greatest diameter, after which the wheel is lowered under the influence of its own weight and that of the other members of the cam-movement of which it is a part, until the dampers are again in the closed position.

It will thus be apparent that the time period during which the dampers are open to admit oxygen to the fire chamber, is regulated by the rate of motion of the time-mechanism under control of its escapement-governor and that the extent to which the dampers are opened and the proportionate lengths 0r their opening and closing movements are predetermined by the shape and size of the cam.

By adjusting the contact wheel from one step of the cam to another or by inter-Chang ing the cam with another of different shape, the extentto which the dampers are opened and the proportionate lengths of the gradual opening and closing movements of the dampers may be Varied to any desired degree.

In order to preheat the air entering the furnace past the gradually opening dampers and to diffuse the same so as to spread evenly over the area of the fuel bed, the door may be provided with a series of battle plates as shown at 4:0 in Figure 3. I

The admission of air to the fire chamber is by the adjustments hereinbefore described readily regulated to correspond to the requirements of the fuel supplied to the fire and a substantially perfect combustion of the gases emanating from the burning fuel, resulting in the saving of all heat units, and the elimination of smoke may thus be effected.

When it is desired to close the fire door Without actuating the dampers, the pawl 22 is disengaged from the notched wheel 28 as shown in broken lines in Figure 2.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1. Oxidizing apparatus for furnaces comprising in combination with the combustion chamber and fire door of a furnace, a damper controlling the admission of air to the combustion chamber, and means actuated by movement of said fire door to gradually open the damper to a predetermined extent after the fire door has been closed and reclose the same. I

2. Oxidizing apparatus for furnaces comprising in combination with the combustion chamber and fire door of a furnace, a damper controlling the admission of air to the 001m open the damper after the fire door has been closed and reclose the same at a predetermined rate.

4. Oxidizing apparatus for furnaces comprising in combination with the combustion chamber and fire door of a furnace, a damper controlling the admission of air to the combustion chamber, and means actuated by movement of said fire door to gradually open the damper at a predetermined rate and to a predetermined extent after the fire door has been closed and reclose the same.

5. Oxidising apparatus for furnaces comprising in combination with the combustion chamber of a furnace, a movable element, a damper controlling admission of air to the combustion chamber, a rotary cam, means to open the damper by movement of the cam, and mechanism for operation of the cam, actuated by movement of said element.

6. In a furnace having a fire door and a damper controlling the admission of air to the furnace, means actuated by movement of the fire door to open the damper after the fire door has been closed and then close the damper.

In testimony whereof I have afiixed my si nature.

ARTHUR O. HIGINBOTHAM. 

